FIG. 1 illustrates an example of an existing variable stiffness guidewire system. As shown in FIG. 1, the guidewire 10 is shown inside the aorta A of a patient, wherein the guidewire 10 is shown inserted through a proximal opening of a catheter hub 12 of a catheter 14 and extending out of a distal opening or lumen 16 of the catheter 14. The guidewire 10 shown in FIG. 1 has the ability to obtain variable stiffness to allow it to travel through different arterial branches and also be stable such that the weight of the catheter 14 and/or other instruments (e.g. balloon catheter, sensors) or drugs may be delivered to the desired location of the patient during a medical procedure. The stiffness of the guidewire 10 is variably adjusted at the proximal end by the physician by pulling a head (not shown) of the guidewire away a desired distance from the coil body 18 of the guidewire. However, the head of the guidewire 10 is small in diameter such that pulling the head away from the coil body 18 usually requires the assistance of a tool 20.
As shown in FIG. 1, the tool 20 is significantly larger than the guidewire 10 which allows the user to comfortably manipulate the tool 20 and guidewire 10. However, this configuration of guidewire 10 and tool 20 is disadvantageous considering that the tool 20 is relatively larger in diameter than that of the guidewire 10. Thus, the relatively larger tool 20 does not allow loading and/or unloading of other components over the catheter 14 at its proximal end 12 without first removing the tool 20 from the guidewire 10. Removing the tool 20 may cause the loss of tension between the head and coil body of guidewire 10, thereby effectively causing loss in the desired stiffness and stability in the guidewire to deliver the instruments or drugs to the desired location within the patient.
Accordingly, a need exists for a variable stiffness guidewire system and tool which allows adjusting of the guidewire stiffness as well as maintaining that stiffness to allow loading and unloading of instruments or drugs to the desired location within the patient without losing or compromising the maintained stiffness in the guidewire.